Quick Facts: Mechanics of Granular Materials (MGM)

The Mechanics of Granular Materials (MGM) project studied how cohesionless granular materials, like sand, deform under pressure. The microgravity environment of the space shuttle provided a laboratory for testing these materials under low-stress conditions, and may help us better understand how to work with sand and soil on Earth and, one day, on the Moon. (Courtesy NASA/Johnson Space Center)

Mission Introduction

The Mechanics of Granular Materials (MGM) project studied how cohesionless granular materials, like sand, deform under pressure. The microgravity environment of the space shuttle provided a laboratory for testing these materials under low-stress conditions, and may help us better understand how to work with sand and soil on Earth and, one day, on the Moon.

The project is a series of microgravity experiments designed to achieve quantitative understanding of the constitutive properties and deformation behavior of granular materials at very low confining pressure (effective stress) levels. The MGM experiments were conceived and designed to utilize the microgravity environment of low earth orbit and have provided new and unique experimental results for testing theories on the mechanical behavior of terrestrial granular materials at low stress levels realizable in the absence of gravitational body forces.

The MGM experiment was initiated by Dr. Nicholas C. Costes in 1976. The PI, Stein Sture joined Dr. Costes’ effort in 1977. It was reviewed and adopted by NASA’s Physics and Chemistry Experiments in Space (PACE) working group in 1977. The MGM project has in the intervening years been subjected to 7 science peer reviews, including a high level review effort conducted by Dr. Robert Schrieffer (Nobel Prize, 1974). Eighteen different academicians and four industry researchers have participated at the various peer reviews. In addition, the project has been subjected to numerous internal NASA (MSFC, ARC, NASA Headquarters) and NAS/NRC program reviews. While the project started at MSFC, it was for two years (1980-1982) managed by ARC, but returned to MSFC. The project was selected for space flight in 1991, when detailed apparatus concept design efforts began. While all early science efforts took place at MSFC and the University of Colorado Boulder, apparatus design and manufacturing was carried out at Sandia National Laboratories.

LASP became an important partner in the project in 1993, aiding in the first set of MGM experiments on STS-79, where three tests were successfully carried out. LASP assumed responsibility for missions following STS-79, successfully carrying out six additional experiments on STS-89.